Supreme Court Redefines “Definiteness” Test for Patent Claims: Court Strikes Down Federal Circuit Standard for Determining Whether Patent Claim Meets Definiteness Requirement of 35 U.S.C. § 112, ¶ 2

Sullivan & Cromwell LLP - June 3, 2014

In Nautilus, Inc. v. Biosig Instruments, Inc., the Supreme Court rejected the long-standing Federal Circuit test for determining whether a patent claim meets the “definiteness” standard of 35 U.S.C. § 112, ¶ 2.  Under the Federal Circuit test rejected by the Court, a claim was sufficiently definite to meet the statutory requirement if it was “amenable to construction” and not “insolubly ambiguous.”  In Nautilus, the Supreme Court unanimously held that the proper test is whether the patent claims, “read in light of the specification . . . and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”  The Court vacated the Federal Circuit’s decision and remanded for further consideration of the patent at issue under the newly defined legal standard.